One of the most striking features of gene expression in cells infected with many different viruses is that there is an inhibition of translation of host mRNAs while viral mRNAs are being translated. This viral control of translation plays a critical role in viral pathogenesis in intact animal hosts. This proposal is focused on understanding the mechanism by which the prototype negative strand RNA virus, vesicular stomatitis virus (VSV), interacts with the translation initiation factor complex eIF4F. eIF4F is a multi-protein complex, and its function is know to be the target of many viruses such as poliovirus, adenovirus and rotavirus. The aims of this project are to determine how host VSV infection causes the dephosphorylation of eIF4E, the cap-binding subunit of the eIF4F complex. This will be accomplished by directly analyzing the activity of the eIF4E and eIF4E binding protein (eIF4E-BP1) kinase and phosphatase activity in infected cell lysates, and by determining whether the eIF4E kinases are dissociated from eIF4F during VSV infection. Additionally, the aims of this proposal are to determine whether there are additional changes to the protein makeup of the eIF4F protein complex by using standard affinity isolation techniques followed by immunoblot analysis and/or mass-spec sequencing following complex purification. These experiments will help understand how VSV, a virus that produces 5' capped, and 3' polyadenylated mRNAs manages to dominate the host translation apparatus, excluding cellular capped and polyadenylated host mRNA and translating its own.